The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingCenter airbag sensor assembly malfunction
Description
The center airbag sensor consists of the airbag sensor, the safing sensor,
the drive circuit, the diagnosis
circuit and the ignition control.
If the center airbag sensor receives signals from the airbag sensor, it
determines whether or not the srs
should be activated.
Dt ...
Diagnosis system
Check dlc3
The ecm uses iso 15765-4 for communication. The
terminal arrangement of the dlc3 complies with sae
j1962 and matches the iso 15765-4 format.
If the result is not as specified, the dlc3 may have a
malfunction. Repair or replace the harness and
connector.
Hint:
Conn ...
Ts and cg terminal circuit
Description
If the vehicle is stationary during sensor check mode, speed sensor
malfunctions cannot be detected. The
vehicle must be driven for speed sensor malfunctions to be detected.
Hint:
Change to sensor check mode by connecting terminals tc and cg of the dlc3,
and turning the ignitio ...